[0.6.0] Turn off email verification if no email client

[abelanger5]

Pull request type

Please check the type of change your PR introduces:

• Bugfix
• Feature
• Other (please describe): be able to turn off email verification for locally runnable + dev versions

Pull request checklist

Please check if your PR fulfills the following requirements:

• If it's a backend change, tests for the changes have been added and go test ./... runs successfully from the root folder.
• If it's a frontend change, Prettier has been run
• Docs have been reviewed and added / updated if needed

What is the current behavior?

Email verification is always on.

What is the new behavior?

If there's no email client, turn email verification off.

Technical Spec/Implementation Notes

To test: remove email env variables and make sure new users don't require verification.